Mexico’s Navy has issued a Mar de Fondo alert for Puerto Vallarta and other Pacific ports, warning of elevated surf and dangerous currents from Sunday, August 17, through Tuesday, August 19.
Forecasters expect waves of 6 to 8 feet with long intervals of around 20 seconds. These swells, generated by distant storms, can create powerful rip currents and shoreline surges even when skies are clear. The Navy urges extra caution for swimmers, surfers, and small craft operators.
The alert covers Puerto Vallarta as well as neighboring coasts in Nayarit and Sinaloa. Long-period waves may appear calm between sets but can suddenly surge higher on beaches and at harbor entrances. Authorities warn that this makes rip currents especially hazardous for beachgoers.
Mar de Fondo refers to a train of long, rolling swells that travel hundreds of kilometers. They are common on Mexico’s Pacific coast, particularly from May to November. The sets build energy offshore, then rise sharply in shallow water, catching many by surprise.
Safety recommendations
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Follow lifeguard and Civil Protection instructions
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Keep small boats secured above the wash line
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Avoid walking close to breaking waves
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Postpone swimming and water activities until conditions improve
Mar de Fondo events can mislead visitors, as the sea may appear calm while hidden currents pull beneath the surface. For locals, beach businesses, and port operators, the Navy recommends keeping equipment away from the tide line and monitoring the swells through Tuesday.
The goal, officials say, is to safeguard both people and property until the alert passes.